Study Of Robust Watermarking Algorithm Of Digital Image

The wavelet analysis was born more than ten years ago. Its theory develops to be flawless in a surprising speed, and its applying domain extends from math signal processing to physics astronomy geography biology chemical etc. Wavelet is considered to be another powerful analysis tool after Fourier analysis. Now a new tide of MRA is coming. MRA will take profound influence to every science.Digital watermark is a technology of copyright. According to embedding certain information into the cover image, when there is a dispute about its copyright happens, the owner can extract the information to prove the ownership. With the rapidly development of network, its actual mean attract more and more scientist.In the main work of this paper, we first apply DCT and wavelet to the study of robust watermarking algorithm. An algorithm whose ability of against attack is remarkable improved is proposed. After the analysis of the flaw of wavelet used in image processing, we try to applying MRA into the study of robust watermarking algorithm and according to the experiment we proved that this algorithm has certain ability against attack. At last, we proposed an robust algorithm based on contourlet developed from ridgelet. It also has well ability against popular attack, compound and geometric attack. This paper mainly including:In chapter 1, the preface introduces the history overview and the outlook of wavelet MRA amd watermark. The main work of this paper is also gived.Chapter 2 expound the basic theory of wavelet related to our result.In chapter 3 we proposed the study of robust digital watermark algorithm based on DWT and DCT.Chapter 4 grasps the basic theory of Ridgelet first, and then is the study of watermark algorithm based on Ridgelet.In the last part chapter 5 we'll briefly introduces the main thought of Contourlet and proposed an robust algorithm based on it.